Existing conveyance devices, such as elevators, are equipped with sensors for detection of people or passengers. The sensors, however, are unable to capture many passenger behaviors. For example, a passenger that slowly approaches an elevator may have the elevator doors close prematurely unless a second passenger holds the elevator doors open. Conversely, the elevator doors may be held open longer than is necessary, such as when all the passengers quickly enter the elevator car and no additional passengers are in proximity to the elevator.
Two-dimensional (2D) and three-dimensional (3D) sensors may be used in an effort to capture passenger behaviors. Both types of sensors are intrinsically flawed. For example, 2D sensors that operate on the basis of color or intensity information may be unable to distinguish two passengers wearing similar colored clothing or may be unable to discriminate between a passenger and an object in the background of similar color. 3D sensors that provide depth information may be unable to generate an estimate of depth in a so-called “shadow region” due to a difference in distance between an emitter/illuminator (e.g., an infrared (IR) laser diode) and a receiver/sensor (e.g., an IR sensitive camera). What is needed is a device and method of sufficient resolution and accuracy to allow explicit and implicit gesture-based control of a conveyance. An explicit gesture is one intentionally made by a passenger intended for communication to the conveyance controller. An implicit gesture is where the presence or behavior of the passenger is deduced by the conveyance controller without explicit action on the passenger's part. This need may be economically, accurately, and conveniently realized by a particular gesture recognition system utilizing distance (called hereafter the “depth”).